Well as I promised before that I will keep you updated on the progress of the untethered userland jailbreak for iOS 5.0.1 for iPhone (4s included), iPod and iPad. The recent notification published on Pod2g's blog regarding the latest progress he found during finishing his work to present us an untethered jailbreak even for the A5 devices.

And he said that the attempts was not successful to untether jailbreak the iPhone 4s because of "processor cache issues". He added that he almost there, however failed to identify what's the problem, but it could be from the Cortex-A9 cache management.